1. Field of the Invention
The present invention relates to an image formation apparatus having a sheet processor, and more particularly, to an image formation apparatus having a sheet processor for stacking and sorting sheets ejected from the apparatus, the processor having a punching means for punching holes in sheets.
2. Description of the Related Art
In a conventional sheet sorter for processing sheets, approximately 20 trays for stacking sheets (hereinafter referred to as xe2x80x9cbinsxe2x80x9d) are arranged in such a manner as to be mutually separated by a specified distance; sheets ejected from the image formation apparatus sequentially in a specific period of time are carried in order into specified bins by a carrying means.
Regarding a method for punching holes in sheets, which is employed in such a sheet sorter, a method for punching holes into a pile of sheets placed in the bins is known. This method, however, has some problems: while punching of holes is being performed, the subsequent sheet cannot be carried to the sheet processor, since punching of holes is performed on a pile of sheets. In addition, depending on punching capability, it is necessary to suspend the carrying of sheets from the image formation apparatus to the sheet processor every time holes are punched into a pile of sheets. As a result, these problems hinder the improvement of processing speed.
Accordingly, for example, a method for respectively punching holes in each of the sheets ejected from the apparatus sequentially in a specified period of time is known; furthermore, there is known a method in which punching is performed without an increase in sheet processing time, regardless of whether punching processing is performed, by disposing a punching means composed of a punch and a die on a sheet carrying path, and bringing a sheet carrying speed into synchrony with a punching speed so as to perform punching without stopping the sheet which is being carried.
In the conventional examples, when an action of punching is selected through the image formation apparatus, the action of punching is required to be input before the starting action for forming an image in the apparatus is input. Thus, when image formation is started without setting of punching, image formation by the apparatus must be suspended.
The present invention has been made to overcome these problems. It is an object of the present invention to provide an image formation apparatus having a sheet processor in which an action setting of a punching unit can be performed during a specified period of time, even after image formation starts.
According to an aspect of the present invention, there is provided an image formation apparatus having a main section and a sheet processor section, which includes; an image forming unit for forming an image on a sheet; an ejecting unit for ejecting the sheet on which the image is formed by the image forming unit, wherein the image forming unit and the ejecting unit are contained in the main section of the image formation apparatus; a punching unit for punching at least one hole in a sheet ejected from the main section of the image formation apparatus, the punching unit being disposed in the processor; and a punch action selection unit for selecting punch action. The image formation apparatus has a controlling unit for controlling the punch action selecting unit in such a manner that a punch action selection by the punching unit is permitted during a specified period of time after start of image formation signal is input.
The image formation apparatus having a sheet processor described above may also include a sheet detecting unit for detecting the arrival of a sheet at the sheet processor; a specified period of time taken after the starting of the image formation is input may coincide with the period of time taken for the first sheet upon which an image has been formed from the main section of the image formation apparatus to arrive at the sheet detecting unit.
Preferably, the sheet detecting unit described above is an entry sensor which is arranged upstream of the punching unit.
According to an another aspect of the present invention, there is provided an image formation apparatus which includes: an image forming unit for forming an image on a sheet; a carrying path for guiding the sheet on which the image is formed by the image forming unit; an ejecting unit for ejecting the sheet guided by the carrying path; a stacking unit for stacking the sheet ejected by the ejecting unit; a processing unit disposed in the carrying path for performing processing on the sheet guided by the carrying path; a selection signal input unit for inputting a selection signal for selecting a mode either for operating the processing unit or for not operating the same; a start signal input unit for inputting a start signal for starting an image formation; and a controlling unit for controlling the processing unit according to the mode selected by the input selection signal when the selection signal is input after the start signal is input.
Based on the arrangement above, when a punch action is selected by the punch action selection unit, the sheet upon which an image has been formed is ejected and carried from the main section of the image formation apparatus is punched by the punching unit. Even after input of the starting of the image forming action performed by the main section of the image formation apparatus, as long as it occurs during a specified period of time, a selection of a punch action by the punch action selection unit can be accepted. Thus, the setting of the punch action selection unit within the specified period of time permits a punch action by the punching unit to be performed, even if the action setting of the punch action selection unit is forgotten; and there is no need to pause the image formation apparatus halfway through a job, so that a satisfactory use environment of the apparatus can be obtained.